Ubiquitin



Ubiquitin (UBB) is found in almost all cells. It binds to proteins tagging them for destruction in the proteasome. UBB is activated by the UBB-activating enzymes E1, E2 and E3. UBB+1 is a frameshifted mutant of UBB observed in several diseases. A dimer of UBB (DiUBB) is formed by linkage of K48 to the C-terminus of a second UBB molecule. At least 4 UBB molecules are needed to tag a protein for the proteasome. The images at the left and at the right correspond to one representative Ubiquitin, i.e. the NMR structure of human Ubiquitin (1d3z).

Additional Resources
See: Ubiquitin Structure & Function for additional information.

Ubiquitin
2kn5, 2klg, 2jzz, 2pe9, 2pea, 1g6j, 1d3z – hUBB – NMR - human

2ojr, 2nr2, 2fcq, 1ubi, 1ubq, 1xqq, 3ons - hUBB

2zcb, 2gbj, 2gbk, 2gbm, 2gbn, 2gbr, 2fcm, 2fcn, 2fcs, 1yiw, 1yj1, 1sif, 1ogw - hUBB (mutant)

3n30 – hUBB+Zn

3n32 – hUBB+Pt

1c3t, 1ud7 - hUBB (mutant) - NMR

1gjz, 2l3z – hUBB N-terminal – NMR

1e0q - hUBB N-terminal (mutant) – NMR

2k39 – UBB – Xenopus laevis – NMR

2jwz, 1zw7 – yUBB (mutant) – yeast

1cmx – yUBB (modified)

2zcc – bUBB - bovine

Ubiquitin+UBB-activating enzymes
3cmm – yUBB+E1

3k9p, 3a33 – hUBB+E2

2gmi - hUBB+E2+MMS2

2kjh, 1zgu – hUBB (mutant)+E2

3jvz, 3jw0 – hUBB+E2+E3

Ubiquitin+1 mutant
2kx0 – hUBB+1 – human – NMR

3k9o – hUBB+1+E2

Ubiquitin dimer
2xk5, 3nob, 2xew, 3h7p, 3h7s, 2w9n, 2jf5 – hDiUBB

3m3j, 1aar – bDiUBB

2bgf – hDiUBB – chemical relaxation

Ubiquitin tetramer
3alb, 3hm3, 2o6v, 1f9j, 1tbe – tetra-hUBB

Ubiquitin bound to protein
3ofi – hUBB+insulin protease 3n3k, 3ifw, 3kvf, 3kw5, 3irt, 3mtn, 3ihp – hUBB (mutant)+hUBB carboxyl-terminal esterase catalytic domain

3i3t, 2ibi, 2ayo, 1nbf - hUBB+hUBB carboxyl-terminal hydrolase catalytic domain

2khw – hUBB+immunoglobulin G-binding protein G

1yx5, 1yx6 - hUBB+26S proteasome non-ATPase regulatory subunit – NMR

2k6d – hUBB+SH3 domain-containing kinase-binding protein – NMR

2z59 – hUBB+mProtein Adhesion-regulating molecule 1

2jy6 – hUBB+hUbiquilin – NMR

3by4, 3c0r – hUBB+yUBB thioesterase

2hth – hUBB+vacuolar protein sorting protein

1s1q – hUBB+tumor susceptibility gene 101 protein

1q5w – hUBB+NPL4 zinc-fingers

2k8b, 2k8c – hUBB+phospholipase A2-activating protein fragment

2ktf – hUBB+hDNA polymerase IOTA

2l0f – hUBB (mutant)+hDNA polymerase IOTA

2kwu, 2kwv - hUBB+mDNA polymerase IOTA – mouse

2l0t – hUBB+signal transducing adapter molecule 2

3o65 – hUBB+ataxin-3-like protein josephin domain

3oj3 – hUBB+tumor necrosis factor -induced protein 3

3phd – hPolyUBB+histone deacetylase 6

3prm, 3prp – hUBB+protein L

3pt2 – hUBB+RNA polymerase OTU domain

1uzx – bUBB+VPS23 UEV

2hd5 - bUBB+hUBB carboxyl-terminal hydrolase catalytic domain

3ldz – bUBB+signal transducing adapter molecule

1v80, 1v81 – bUBB/L40 ribosomal protein fusion - NMR

2dx5, 1p3q - bUBB+vacuolar protein sorting protein

2c7m, 2c7n, 2fid, 2fif – bUBB+RAB guanine nucleotide exchange factor

2d3g – bUBB+HRS-UIM

1wrd – bUBB+TOM1 GAT domain

1wr6, 1yd8 - bUBB+GGA3 GAT domain

1uzx – bUBB+VPS23 UEV

2kdi – yUBB/UIM fusion

2jt4 – yUBB fragment+cytoskeleton assembly control protein

1q0w - yUBB+vacuolar protein sorting protein

2g3q – yUBB+EDE1 UBA

1wr1 – yUBB+DSK2P UBA

1otr – yUBB+CUE2

Ubiquitin dimer bound to protein
3a9j, 3a9k, 2wwz, 2wx0, 2wx1 – hDiUBB+mitogen-activated protein kinase

3jsv, 2zvn, 2zvo – hDiUBB+NF-κ-b essential modulator

2kde, 2kdf – DiUBB+26S proteasome non-ATPase regulatory subunit – NMR

3a1q – mDiUBB+UBB interaction motif-containing protein

3dvg, 3dvn – hDiUBB+IGG1 fab light&heavy chains

2znv – mDiUBB+hAMSH-like protease

Ubiquitin + ions
3h1u – bUBB+Cd

3ehv, 3eec, 3efu – hUBB+ions